In the world of Woroch, most stats can be categorized with two letters. XP, HP, MP, and AC, with the exception being DMG. XP, or experience points, is how intelligent races know how far or how close they are to leveling up. At level 1, the required XP is 100, but it doubles from there. For example, LVL 2 requires 200, LVL 3 requires 400, and so on. Because of this, most of the population of Woroch is lower than LVL 10. Most adventurers are between LVLs 10 and 20, while a few of the elite are between 20 and 30.
( BTW, Leveling up from 50 to 51 requires 112,589,990,684,262,400 XP points. This is the main reason why you'll rarely see me report anybody as higher than LVL 30. Even gods are barely LVL 100 )
HP, Health Points, are correlated with how much health a person has. Usually, this stat's base value depends solely on race.
MP, Mana Points, is similar to mana. All 'magic' and all 'skills' use a specific amount of MP, though Origin Magic is the only exception, as all moves from Origin Magic will have varying MP costs.
Finally, AC, Armor Class. Unlike HP and MP, this stat won't rise when one levels up. Only dungeon bosses, which grow in strength when the core levels up, will have their AC rise. Instead, this can only be raised through the use of artifacts and armor.
DMG, which is introduced early in the story, is how much damage an ordinary physical attack gives per attack. This stat is raised through artifacts as well, but it isn't always constant. For example, an iron sword will usually give +10 DMG to it's user, so the user will deal 10+race damage per attack. Certain skills can also raise DMG, such as 『 Combat Expertise 』, which deals another 10 damage.
( Lets say a Goblin, which has 5 AC, is attacked by somebody who does 20 DMG. The Goblin's AC will negate 5 DMG, then ignore everything else. The Goblin, which has 10 HP, will take 15 DMG and die. Simple, right? Because of this system, anything that has an AC over what their attackers can deal will never actually get hurt )
For DMG, however, there is another exception. Critical Hits, which are attacks that are dealt directly against an opponents body- meaning the armor didn't come between the attack and the target- ignore AC entirely.
( The Goblin from earlier, who has 5 AC, has been dealt a Critial Hit. The attack, which is from the same attacker earlier, deals 20 DMG after ignoring the 5 AC. The goblin is dead regardless, but at least the attacker can brag about it to his teammates )
Btw, because a friend of mine asked: This story does not have SP, or stamina points, nor will it ever use something similar. Stamina is largely dependent on two things: The user's physical state (Base HP), and their physical body. That's why Aureys is so much faster than everybody around him- because he has so much HP.
If you have any further questions, please let me know.